/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *    SaveBuffer.java
 *    Copyright (C) 2000 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.gui;

import weka.gui.Logger;

import java.io.File;
import java.io.FileWriter;
import java.io.Writer;
import java.io.BufferedWriter;
import java.io.PrintWriter;

import java.awt.Component;
import javax.swing.JFileChooser;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JDialog;

/**
 * This class handles the saving of StringBuffers to files. It will pop up a
 * file chooser allowing the user to select a destination file. If the file
 * exists, the user is prompted for the correct course of action, ie.
 * overwriting, appending, selecting a new filename or canceling.
 * 
 * @author Mark Hall (mhall@cs.waikato.ac.nz)
 * @version $Revision 1.0 $
 */
public class SaveBuffer {

	/** The Logger to send messages to */
	private Logger m_Log;

	/** The parent component requesting the save */
	private Component m_parentComponent;

	/** Last directory selected from the file chooser */
	private String m_lastvisitedDirectory = null;

	/**
	 * Constructor
	 * 
	 * @param log
	 *            the logger to send messages to
	 * @param parent
	 *            the parent component will be requesting a save
	 */
	public SaveBuffer(Logger log, Component parent) {
		m_Log = log;
		m_parentComponent = parent;
	}

	/**
	 * Save a buffer
	 * 
	 * @param buf
	 *            the buffer to save
	 * @return true if the save is completed succesfully
	 */
	public boolean save(StringBuffer buf) {
		if (buf != null) {
			JFileChooser fileChooser;
			if (m_lastvisitedDirectory == null) {
				fileChooser = new JFileChooser(new File(
						System.getProperty("user.dir")));
			} else {
				fileChooser = new JFileChooser(m_lastvisitedDirectory);
			}

			fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
			int returnVal = fileChooser.showSaveDialog(m_parentComponent);
			if (returnVal == JFileChooser.APPROVE_OPTION) {
				File sFile = fileChooser.getSelectedFile();
				m_lastvisitedDirectory = sFile.getPath();

				if (sFile.exists()) {
					Object[] options = new String[4];
					options[0] = Messages.getInstance().getString(
							"SaveBuffer_Save_Options_0_Text");
					options[1] = Messages.getInstance().getString(
							"SaveBuffer_Save_Options_1_Text");
					options[2] = Messages.getInstance().getString(
							"SaveBuffer_Save_Options_2_Text");
					options[3] = Messages.getInstance().getString(
							"SaveBuffer_Save_Options_3_Text");

					JOptionPane jop = new JOptionPane(Messages.getInstance()
							.getString("SaveBuffer_Save_JOptionPane_Text"),
							JOptionPane.QUESTION_MESSAGE, 1, null, options);
					JDialog dialog = jop
							.createDialog(
									m_parentComponent,
									Messages.getInstance()
											.getString(
													"SaveBuffer_Save_Dialog_JopCreateDialog_Text"));
					dialog.setVisible(true);
					Object selectedValue = jop.getValue();
					if (selectedValue == null) {
					} else {
						for (int i = 0; i < 4; i++) {
							if (options[i].equals(selectedValue)) {
								switch (i) {
								// append
								case 0:
									return saveOverwriteAppend(buf, sFile, true);
									// overwrite
								case 1:
									return saveOverwriteAppend(buf, sFile,
											false);
									// pick new name
								case 2:
									return save(buf);
									// cancel
								case 3:
									break;
								}
							}
						}
					}
				} else {
					saveOverwriteAppend(buf, sFile, false); // file does not
															// exist
				}
			} else {
				return false; // file save canceled
			}
		}
		return false; // buffer null
	}

	/**
	 * Saves the provided buffer to the specified file
	 * 
	 * @param buf
	 *            the buffer to save
	 * @param sFile
	 *            the file to save to
	 * @param append
	 *            true if buffer is to be appended to file
	 * @return true if save is succesful
	 */
	private boolean saveOverwriteAppend(StringBuffer buf, File sFile,
			boolean append) {

		try {
			String path = sFile.getPath();
			if (m_Log != null) {
				if (append) {
					m_Log.statusMessage(Messages
							.getInstance()
							.getString(
									"SaveBuffer_SaveOverwriteAppend_Log_StatusMessage_Text_First"));
				} else {
					m_Log.statusMessage(Messages
							.getInstance()
							.getString(
									"SaveBuffer_SaveOverwriteAppend_Log_StatusMessage_Text_Second"));
				}
			}
			PrintWriter out = new PrintWriter(new BufferedWriter(
					new FileWriter(path, append)));
			out.write(buf.toString(), 0, buf.toString().length());
			out.close();
			if (m_Log != null) {
				m_Log.statusMessage(Messages
						.getInstance()
						.getString(
								"SaveBuffer_SaveOverwriteAppend_Log_StatusMessage_Text_Third"));
			}
		} catch (Exception ex) {
			ex.printStackTrace();
			if (m_Log != null) {
				m_Log.logMessage(ex.getMessage());
			}
			return false;
		}

		return true;
	}

	/**
	 * Main method for testing this class
	 */
	public static void main(String[] args) {
		try {
			final javax.swing.JFrame jf = new javax.swing.JFrame(Messages
					.getInstance().getString("SaveBuffer_Main_JFrame_Text"));
			jf.getContentPane().setLayout(new java.awt.BorderLayout());
			weka.gui.LogPanel lp = new weka.gui.LogPanel();
			javax.swing.JButton jb = new javax.swing.JButton(Messages
					.getInstance().getString("SaveBuffer_Main_Jb_JButton_Text"));
			jf.getContentPane().add(jb, java.awt.BorderLayout.SOUTH);
			jf.getContentPane().add(lp, java.awt.BorderLayout.CENTER);
			final SaveBuffer svb = new SaveBuffer(lp, jf);
			jb.addActionListener(new java.awt.event.ActionListener() {
				public void actionPerformed(java.awt.event.ActionEvent e) {
					svb.save(new StringBuffer(Messages.getInstance().getString(
							"SaveBuffer_Main_Svb_Save_Text")));
				}
			});

			jf.addWindowListener(new java.awt.event.WindowAdapter() {
				public void windowClosing(java.awt.event.WindowEvent e) {
					jf.dispose();
					System.exit(0);
				}
			});
			jf.pack();
			jf.setVisible(true);
		} catch (Exception ex) {
			ex.printStackTrace();
			System.err.println(ex.getMessage());
		}
	}
}
